Man stabbed and shot twice while heading to morning prayers in US city of Houston, witnesses say.

A Muslim doctor in the US state of Texas has been shot and stabbed while on his way to a mosque for morning prayers, local reports said.

The victim, identified as Arslan Tajammul, an eye specialist, had parked his car and was walking towards Madrasah Islamiah in the city of Houston, when he was approached by three men, according to KTRK.

Without any warning, the doctor was stabbed, before one of the men reportedly pulled out a gun and shot him twice.

The victim was able to ask for help near the mosque entrance, as the the attackers made their escape, witnesses told authorities.

The Houston Police District said the victim was taken by ambulance to a hospital, where he will remain in the intensive care unit for 24 hours.

"These anti-Muslim attacks need to stop. Innocent people are getting hurt," Mufti Mohammed Wasim Khan, a Madrasah Islamiah official, said before adding that the victim was in stable condition.

"This is what they want, Americans attacking fellow Americans."

Mustafaa Carroll, executive director of the Houston-based Council on American-Islamic Relations (CAIR) in Texas, said it was too early to know what motivated the attack.